AbstractThis thesis places dung firmly at the centre of livestock farming. It tests the overarching hypothesis that intentional management of dung as a critical resource on-farm has multiple benefits that improve the resilience of beef production systems.
Dung is a primary resource in beef production systems. This importance of dung as an organic fertiliser that recycles nutrients in agricultural systems is widely recognised and understood. The connection between disease, dung and its management through diet choice for beef cattle has received far less attention.
In this study, the cattle diet, both intake and forage management, significantly influenced the rate of bulk and biochemical (fibre fractions, protein, lipids, carbohydrates, organic matter, ash and micronutrients) dung degradation over 84 days under three forage management treatments on the North Wyke Farm Platform. Site-specific factors were the primary drivers of bulk dung degradation; 70% of degradation was driven by field site and 4% by dung type.
Non-target impacts of anthelmintics pose a risk to dung fauna that moderate dung degradation. A multiple-regression model predicted that targeted selective treatments (TST) created refugia for dung-breeding fly Scathophaga stercoraria and that proportions of treated cattle (55%) was more influential than effective dung drug concentrations (13%).
Effective TST programmes rely on practical diagnostic tools. A non-invasive protocol was developed for the quantification of immuno-markers (immunoglobulins and lactoferrin) in dung for gastrointestinal health assessment.
The anecdotal benefits of increasingly popular ‘mob grazing’ were supported by case studies of factors including pasture performance, reduced gastrointestinal nematode (GIN) burden, and soil organic matter content over a grazing season in a UK-wide study.
The conclusion of this multidisciplinary study is that dung management has a critical role to play in a systems-level understanding of beef production and that optimisation relies on a quantitative understanding of the relationships between wider biological processes on farms.
|Date of Award||19 Jun 2018|
|Supervisor||Jenni Dungait (Supervisor) & Eric Morgan (Supervisor)|